What rotational kinetic energy is
Rotational kinetic energy is the energy an object possesses because of its rotation about an axis. It is the rotational counterpart of the familiar linear kinetic energy formula, ½mv².
The formula used
This calculator uses KE = ½Iω², where I is the object’s moment of inertia (its rotational equivalent of mass, depending on mass distribution and shape) and ω is its angular velocity in radians per second.
Moment of inertia depends on the shape and mass distribution of the object relative to its axis of rotation; common formulas exist for shapes like solid disks, spheres, and rods. For general physics education purposes.
Last reviewed August 2026